In the field of mobile computing, a technique of searching for an optimal travel route based on an origin and a destination has become widespread. The optimal travel route is generally a route in which the cost for travel becomes minimum, e.g., a route with the shortest required time.
Meanwhile, there have been demands to search for a route according to the liking of a user. For example, Patent Literature 1 describes a navigation device configured to search for an optimal route from an origin to a destination using a cost evaluation function, wherein the device changes the weight coefficient of a cost parameter in accordance with the situation of driving (e.g., the day of week or time period). By using the device, a route in accordance with the characteristics of each user can be determined, such that, for example, a route with the shortest required time is selected on a weekday and a route that is easy to drive is selected on a holiday.